malignant rhabdoid tumor

Epidemiology

 infancy and early childhood
 median age: 11 mths
 unbalanced sex ratio (1.5M/1F)

Synopsis

 uncertain histogenesis

Localization

 kidney (renal malignant rhabdoid tumor)

• cysstic renal malignant rhabdoid tumor
   central nervous system
   soft tissues
   paratesticular region (14696145) (3 cases described - 2004)
   mesentery (14507006)

Subtypes

 cystic malignant rhabdoid tumor (cystic MRT)

Predisposition

 rhabdoid tumor predisposition syndrome : constitutional mutation in the SMARCB1 (hSNF5/INI1) gene at 22q11.2 (MIM.601607)

Cytogenetics

 normal karyotype

 22q11 anomalies (8818656)

• 22q11.2 deletion - del(22q) (8818656)
• 22q rearrangements
  • t(1;22)(p36;q11.2) (9491318)
  • t(11;22)(p15.5;q11.23) (7669732, 8188285, 1747867)
  • t(12;22)(q24.3;q11.2-12) (9460503)

 8q24 rearrangements

• t(8;13)(q24;q33) in a malignant rhabdoid tumor of the liver (10640148)

 inv(11)(p13p15) (11004236)

Molecular biology

 LOH at 22q11.2
 LOH at 11p15.5
 inactivating mutation of the SMARCB1 (hSNF5/INI1) gene at 22q11.2 (MIM.601607)

Pathology

 Germline mutations are found in 35% of apparently sporadic RT. (21208904)
 20% of patients with germline mutation develop the disease after 2 years of age. (21208904)
 There is a very high proportion of germ-cell mosaicism or of de novo mutations in RPS (rhabdoid tumor predisposition syndrome). (21208904)
 The 2 years’ overall survival is 7% in mutated and 29% in wild-type patients, mainly due to the worse outcome of RT in younger patients. (21208904)
 There is a high proportion of germline mutations in patients with RT that can be found at any age and up to 60% in the youngest patients. (21208904)
 Genetic counseling is recommended given the low but actual risk of familial recurrence.

Differential diagnosis

 rhabdoid cell tumors

Prognosis

 highly aggressive tumor
 80% mortality rate with frequent metastases, predominantly pulmonary
 better outcome for girls (> 50% survival) than for boys (10%) (one study)

Links

 AGCOH

References

 Frequent hSNF5/INI1 germline mutations in patients with rhabdoid tumor. Bourdeaut F, Lequin D, Brugières L, Reynaud S, Dufour C, Doz F, André N, Stephan JL, Pérel Y, Oberlin O, Orbach D, Bergeron C, Rialland X, Fréneaux P, Ranchere D, Figarella-Branger D, Audry G, Puget S, Evans DG, Pinas JC, Capra V, Mosseri V, Coupier I, Gauthier-Villars M, Pierron G, Delattre O. Clin Cancer Res. 2011 Jan 1;17(1):31-8. PMID: 21208904 (Free)